1. Field of the Invention
This invention relates generally to devices for covering the upper end of a vertical exhaust pipe to prevent the entrance of rain and snow, and pertains more particularly to such a device having a lid which is automatically latched closed when the internal combustion engine is shut down and automatically released when the engine is running.
2. Description of the Prior Art
Pivotal lids have been used for many years to cover the upper ends of vertical exhaust pipes, thereby preventing rain and snow from entering the exhaust pipe and falling down into the internal combustion engine where damage can occur from the resulting rusting or corrosion. For the most part, these covering devices have worked satisfactorily, although difficulties have been encountered as far as opening by wind action. Even more importantly, problems have arisen in the past from vandalism where the vandals open the covering device for the purpose of mischievously introducing foreign matter into the exhaust pipe which substances can seriously damage the internal combustion engine.
One attempt to minimize the likelihood of the exhaust cover inadvertently opening due to wind action is described in U.S. Pat. No. 3,407,720 for EXHAUST COVER, granted Oct. 29, 1968, to Albert M. Westerman. While the disc-like cover or lid illustrated in said patent is free to open when exhaust gases are flowing, if the wind action is sufficiently severe when the engine is shut down, an increase in frictional binding occurs so that there is greater resistance to the external wind forces and the lid, under these conditions, remains closed. Provision is made for the manual opening of the cover from outside should circumstances so warrant.
Another device that has been contrived to obviate the opening from wind action is the device disclosed in U.S. Pat. No. 3,334,932, issued on Aug. 8, 1967, to Henry V. Buresh for TRANSPORT-STORAGE LATCH. In this instance a manual latching operation is required, a hook arrangement being contemplated. The lid or cap remains locked until manually unlatched.
As might be expected, efforts have been made to lock weather covers in a closed position in order to discourage vandalism. An example of such an effort is the padlock arrangement depicted in U.S. Pat. No. 3,667,260, granted to Daniel J. Foote on June 6, 1972, for EXHAUST PIPE PROTECTOR LOCK. It is necessary to manually lock and unlock the cover, a special padlock being contemplated.